From: Andrew Deason <adeason@sinenomine.net>
Date: Fri, 22 Jan 2010 01:42:33 +0000 (-0500)
Subject: Fix afs_AccessOK for dropbox case
X-Git-Tag: openafs-devel-1_5_70~8
X-Git-Url: https://git.openafs.org/?p=openafs.git;a=commitdiff_plain;h=3f89c0feae89e9a255afb8a7f08995412a3f1b79

Fix afs_AccessOK for dropbox case

afs_AccessOK did not check for if we have 'i' rights on a directory, nor
if we were the owner of a file, if we were only checking PRSFS_READ or
PRSFS_WRITE. Thus, it does not correctly address the 'dropbox'
permissions case (if you are the owner of a file and have insert
permissions, you get implicit 'r' and 'w').

Fix this to check for 'i' and ownership when we need to, so the dropbox
special-case check works as intended.

FIXES 126216

Change-Id: Ib629bc30b73bc3965e777747067259451f0adff6
Reviewed-on: http://gerrit.openafs.org/1143
Tested-by: Andrew Deason <adeason@sinenomine.net>
Reviewed-by: Derrick Brashear <shadow@dementia.org>
Tested-by: Derrick Brashear <shadow@dementia.org>
---

diff --git a/src/afs/VNOPS/afs_vnop_access.c b/src/afs/VNOPS/afs_vnop_access.c
index 0a31ac8..f72b6e6 100644
--- a/src/afs/VNOPS/afs_vnop_access.c
+++ b/src/afs/VNOPS/afs_vnop_access.c
@@ -148,15 +148,36 @@ afs_AccessOK(struct vcache *avc, afs_int32 arights, struct vrequest *areq,
 	    /* Avoid this GetVCache call */
 	    tvc = afs_GetVCache(&dirFid, areq, NULL, NULL);
 	    if (tvc) {
-		dirBits = afs_GetAccessBits(tvc, arights, areq);
+		if ((arights & (PRSFS_READ | PRSFS_WRITE))) {
+		    /* we may need to grant implicit 'rw' rights if we have
+		     * 'i' on the parent dir and we are the owner, so check
+		     * for 'i' rights in addition, here */
+		    dirBits = afs_GetAccessBits(tvc, arights | PRSFS_INSERT, areq);
+		} else {
+		    dirBits = afs_GetAccessBits(tvc, arights, areq);
+		}
 		afs_PutVCache(tvc);
 	    }
 	} else
 	    dirBits = 0xffffffff;	/* assume OK; this is a race condition */
-	if (arights & PRSFS_ADMINISTER)
+	if (arights & PRSFS_ADMINISTER) {
 	    fileBits = afs_GetAccessBits(avc, arights, areq);
-	else
+
+	} else if ((dirBits & PRSFS_INSERT) &&
+	          ((arights & (PRSFS_READ | PRSFS_WRITE)) & dirBits) !=
+	           (arights & (PRSFS_READ | PRSFS_WRITE))) {
+
+	    /* if we have 'i' rights in the directory, and we are requesting
+	     * read or write access, AND the directory ACL (dirBits) does not
+	     * already give us the requested read or write access, we need to
+	     * find out if we are the owner for the file ('A' bit), for the
+	     * "throw in R and W if we have I and A" check below */
+
+	    fileBits = afs_GetAccessBits(avc, arights | PRSFS_ADMINISTER, areq);
+
+	} else {
 	    fileBits = 0;	/* don't make call if results don't matter */
+	}
 
 	/* compute basic rights in fileBits, taking A from file bits */
 	fileBits =
@@ -164,8 +185,8 @@ afs_AccessOK(struct vcache *avc, afs_int32 arights, struct vrequest *areq,
 
 	/* for files, throw in R and W if have I and A (owner).  This makes
 	 * insert-only dirs work properly */
-	if (vType(avc) != VDIR
-	    && (fileBits & (PRSFS_ADMINISTER | PRSFS_INSERT)) ==
+	/* note that we know vType(avc) != VDIR from the top-level 'else' */
+	if ((fileBits & (PRSFS_ADMINISTER | PRSFS_INSERT)) ==
 	    (PRSFS_ADMINISTER | PRSFS_INSERT))
 	    fileBits |= (PRSFS_READ | PRSFS_WRITE);